Structural refinement using high-resolution powder X-ray diffraction data of Ca0.5Ti2P3O12, a low-thermal-expansion material

The crystal structure of the title compound has been determined by single crystal X-ray diffraction data collected at 293 K, and refined to a final Rw of 0.057. The crystals are rhombohedral, space group [Formula: see text], with a = 27.134(8) Å, c = 10.933(2) Å, and Z = 18. The mole ratio of Dianin's compound (4-p-hydroxyphenyl-2,2,4-trimethylchroman) to CCl4 is 6:1. The guest molecules are disordered. X-ray powder diffraction was carried out in the temperature range from 10 to 300 K. From this, the thermal expansion coefficients for the a- and c-axes and the volume have been determined. Keywords: thermal expansion, crystal structure, clathrate.

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Topological Analysis of the Electron Density Distribution in the Crystal of 8,9,10,12-Tetrafluoro-o-carborane on the Basis of the High-Resolution X-ray Diffraction Data at 120 K

Inorganic Chemistry ◽

10.1021/ic9807644 ◽

1998 ◽

Vol 37 (22) ◽

pp. 5834-5843 ◽

Cited By ~ 25

Author(s):

Konstantin A. Lyssenko ◽

Mikhail Yu. Antipin ◽

Viatcheslav N. Lebedev

Keyword(s):

High Resolution ◽

Density Distribution ◽

Electron Density ◽

Diffraction Data ◽

Electron Density Distribution ◽

Topological Analysis ◽

X Ray Diffraction ◽

X Ray

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D-67 High-Resolution X-ray Diffraction Data Analysis From The Partly Relaxed Semiconductor Structures

Powder Diffraction ◽

10.1154/1.3176000 ◽

2009 ◽

Vol 24 (2) ◽

pp. 171-171

Author(s):

A. Ulyanenkov ◽

A. Benediktovitch ◽

I. Feranchuk ◽

B. He ◽

H. Ress

Keyword(s):

Data Analysis ◽

High Resolution ◽

Diffraction Data ◽

X Ray Diffraction ◽

X Ray ◽

Semiconductor Structures

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An examination of the thermal expansion of urea using high-resolution variable-temperature X-ray powder diffraction

Journal of Applied Crystallography ◽

10.1107/s0021889805029754 ◽

2005 ◽

Vol 38 (6) ◽

pp. 1038-1039 ◽

Cited By ~ 9

Author(s):

Robert Hammond ◽

Klimentina Pencheva ◽

Kevin J. Roberts ◽

Patricia Mougin ◽

Derek Wilkinson

Keyword(s):

Thermal Expansion ◽

High Resolution ◽

Variable Temperature ◽

X Ray Diffraction ◽

Polymorphic Transformations ◽

X Ray ◽

Thermal Expansion Coefficients ◽

Cell Dimensions ◽

Expansion Coefficients ◽

Unit Cell Dimensions

Variable-temperature high-resolution capillary-mode powder X-ray diffraction is used to assess changes in unit-cell dimensions as a function of temperature over the range 188–328 K. No evidence was found for any polymorphic transformations over this temperature range and thermal expansion coefficients for urea were found to be αa= (5.27 ± 0.26) × 10−5 K−1and αc= (1.14 ± 0.057) × 10−5 K−1.

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Powder X-ray diffraction of Metastudtite, (UO2)O2(H2O)2

Powder Diffraction ◽

10.1017/s0885715615000895 ◽

2016 ◽

Vol 31 (1) ◽

pp. 71-72 ◽

Cited By ~ 3

Author(s):

Mark A. Rodriguez ◽

Philippe E. Weck ◽

Joshua D. Sugar ◽

Thomas J. Kulp

Keyword(s):

Powder Diffraction ◽

Diffraction Data ◽

First Principles ◽

Density Functional ◽

Powder Diffraction Data ◽

Structural Refinement ◽

X Ray Diffraction ◽

Orthorhombic Space Group ◽

X Ray ◽

Unit Cells

There has been some confusion in the published literature concerning the structure of Metastudtite (UO2)O2(H2O)2 where differing unit cells and space groups have been cited for this compound. Owing to the absence of a refined structure for Metastudtite, Weck et al. (2012) have documented a first-principles study of Metastudtite using density functional theory (DFT). Their model presents the structure of Metastudtite as an orthorhombic (space group Pnma) structure with lattice parameters of a = 8.45, b = 8.72, and c = 6.75 Å. A Powder Diffraction File (PDF) database entry has been allocated for this hypothetical Metastudtite phase based on the DFT modeling (see 01-081-9033) and aforementioned Dalton Trans. manuscript. We have obtained phase pure powder X-ray diffraction data for Metastudtite and have confirmed the model of Weck et al. via Rietveld refinement (see Figure 1). Structural refinement of this powder diffraction dataset has yielded updated refined parameters. The new cell has been determined as a = 8.411(1), b = 8.744(1), and c = 6.505(1) Å; cell volume = 478.39 Å3. There are only subtle differences between the refined structure and that of the first-principles model derived from DFT. Notably, the b-axis is significantly contracted in the final refinement as compared with DFT. There were also subtle changes to the U1, O1, and O3 atom positions. Tabulated powder diffraction data (d's and I's) for the Metastudtite have been derived from the refined model and these new values can serve to augment the PDF entry 01-081-9033 with a more updated entry based on observed X-ray powder diffraction data.

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Revisit of α-Chitin Crystal Structure Using High Resolution X-ray Diffraction Data

Biomacromolecules ◽

10.1021/bm801251e ◽

2009 ◽

Vol 10 (5) ◽

pp. 1100-1105 ◽

Cited By ~ 149

Author(s):

Pawel Sikorski ◽

Ritsuko Hori ◽

Masahisa Wada

Keyword(s):

Crystal Structure ◽

High Resolution ◽

Diffraction Data ◽

X Ray Diffraction ◽

X Ray

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Neutron and high-resolution room-temperature X-ray data collection from crystallized lytic polysaccharide monooxygenase

Acta Crystallographica Section F Structural Biology Communications ◽

10.1107/s2053230x15019743 ◽

2015 ◽

Vol 71 (11) ◽

pp. 1448-1452 ◽

Cited By ~ 6

Author(s):

John-Paul Bacik ◽

Sophanit Mekasha ◽

Zarah Forsberg ◽

Andrey Kovalevsky ◽

Jay C. Nix ◽

...

Keyword(s):

High Resolution ◽

Diffraction Data ◽

Room Temperature ◽

X Ray Diffraction ◽

Lytic Polysaccharide Monooxygenase ◽

Data Set ◽

X Ray ◽

Processing Enzymes ◽

Bacteria And Fungi ◽

Polysaccharide Monooxygenase

Bacteria and fungi express lytic polysaccharide monooxgyenase (LPMO) enzymes that act in conjunction with canonical hydrolytic sugar-processing enzymes to rapidly convert polysaccharides such as chitin, cellulose and starch to single monosaccharide products. In order to gain a better understanding of the structure and oxidative mechanism of these enzymes, large crystals (1–3 mm3) of a chitin-processing LPMO from the Gram-positive soil bacteriumJonesia denitrificanswere grown and screened for their ability to diffract neutrons. In addition to the collection of neutron diffraction data, which were processed to 2.1 Å resolution, a high-resolution room-temperature X-ray diffraction data set was collected and processed to 1.1 Å resolution in space groupP212121. To our knowledge, this work marks the first successful neutron crystallographic experiment on an LPMO. Joint X-ray/neutron refinement of the resulting data will reveal new details of the structure and mechanism of this recently discovered class of enzymes.

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Charge Densities and Electrostatic Potentials for Energetic Materials

MRS Proceedings ◽

10.1557/proc-418-49 ◽

1995 ◽

Vol 418 ◽

Author(s):

A. A. Pinkerton ◽

A. Martin

Keyword(s):

High Resolution ◽

Low Temperature ◽

Diffraction Data ◽

Energetic Materials ◽

X Ray Diffraction ◽

X Ray ◽

Charge Densities ◽

Contour Maps ◽

Deformation Density ◽

Dinitramide Salts

AbstractHigh resolution (sinθ/λ < 1.34 Å−1), low temperature (85 K) X-ray diffraction data has been used to map the deformation density and the derived electrostatic potential for three dinitramide salts. The traditional presentation of contour maps has been replaced with 3D views of the molecule. A comparison of the dinitramide ions from each salt is presented.

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Characterizing the Image Forming Particles of Modern Ungilded Daguerreotypes Using XRD and SEM

Microscopy and Microanalysis ◽

10.1017/s1431927619000709 ◽

2019 ◽

Vol 25 (4) ◽

pp. 1037-1051

Author(s):

Patrick Ravines ◽

Alexander Y. Nazarenko

Keyword(s):

High Resolution ◽

Diffraction Data ◽

Regions Of Interest ◽

X Ray Diffraction ◽

Sem Images ◽

Cubic Crystals ◽

X Ray ◽

Silver Amalgam ◽

Crystalline Nature ◽

Scanning Electron

AbstractX-ray diffraction (XRD) and high-resolution scanning electron microscopy (SEM) have been used to characterize the silver mercury amalgam particles resting on the surface that comprise the image of five daguerreotype plates that were not gilded and that were prepared by three different contemporary daguerreotype makers. The regions of interest of the surface that were examined were overexposed, solarized, and highlight (white) areas. The XRD portion of the study shows that the two main silver mercury amalgam particles identified using the International Center for Diffraction Data PF4 + database were the Schachnerite/ζ (zeta) phase amalgam, Ag1.1Hg0.9, and the mercury silver amalgam, Ag0.65Hg0.35. On one of the daguerreotypes a third silver mercury amalgam, Moschellandsbergite, Ag2Hg3, was also identified in small concentrations. High-resolution SEM images corroborate the diffraction data and show that the crystalline nature of the silver mercury amalgam particles on all five plates to be mostly hexagonal, which would correspond to the Schachnerite/ζ (zeta) phase amalgam, and fewer rectangular solid and cubic crystals corresponding to the mercury silver amalgam.

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